The present invention relates to an image formation apparatus having at least copy and printer functions.
The recent advance of digital technology and LAN environments have allowed copying machines to be frequently used as image handling apparatuses which, in addition to a copy function, provide a scanner function and a printer function (i.e., a function of printing characters corresponding to input character code data).
Unlike the copy function in which the user has to directly operate the copying machine, in the printer function, data to be printed are transferred over a LAN or the like to the copying machine and then printed. For this reason, a job spooling facility which is not required with conventional copying machines, i.e., a facility for temporarily saving data to be printed, has become essential.
Thus, when a printer job has been spooled, the user has to wait at the side of the copying machine until the spooled printer job is completed, which may degrade the operability of the copy function.
A conventional interrupt facility adapted to prevent such a situation can force the printer job to be suspended for printing. For example, if an interruption is caused when the 25-th page of 50 pages of printer job is being printed, then copying will be made possible at the termination of printing of the 25-th page.
However, when a printer job is carried out using a sorter facility, a limitation is encountered in specifying receiving (exit) trays of the sorter at copy time. That is, when sheets of paper printed by the printer job have been sorted into some trays of the sorter, sheets copied by copying operation have to be delivered to unused trays in order to prevent the copies from being delivered to the same trays as the printed sheets have been delivered. Therefore, a problem arises in that is it impossible to perform the copying function using the sorter facility.
On the other hand, the user who has directed the machine to perform a printer job will also suffer inconvenience because the printer job in execution may be suspended for a long time by an interruption caused by another user.